Numerical solution of the Pulsatile, non-Newtonian and turbulent blood flow in a patient specific elastic carotid artery

Moradicheghamahi, Jafar; Sadeghiseraji, Jaber; Jahangiri, Mehdi

doi:10.1016/j.ijmecsci.2018.10.046

Cited by 62 publications

(47 citation statements)

References 59 publications

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“…(VI) Finally, the arterial wall was assumed to be an elastic, anisotropic and inhomogeneous material (16,17) while the blood flow was assumed to be the standard K-epsilon (two equations) viscous model, with enhanced wall treatment, non-Newtonian Carreau viscosity modelling {Eq. [1]}, and incompressible fluid (18,19). The five arbitrary layers in the media were provided with the same material properties (shown in Table 1), as is the conventional engineering approach (14).…”

Section: Methodsmentioning

confidence: 99%

“…The major parameters which can influence stress/ strain magnitude in a multilayer carotid artery model and consequently relative interlayer movement, are blood vessel geometry, the mechanical characteristics of the arterial wall and blood pulse pressure (19,20,(25)(26)(27). In our paper, an angio CT based model of a multicomponent Fluid-Solid Interaction (FSI) computational model of a human carotid artery was used to perform shear stress analysis in the arterial wall, and to identify critical stress variations which may cause injury within the wall of the vessel.…”

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confidence: 99%

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Stress distribution in the walls of major arteries: implications for atherogenesis

Mishani¹,

Belhoul-Fakir²,

Lagat³

et al. 2021

Quant Imaging Med Surg

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Background: There is a correlation between the sites of atheroma development and stress points in the arterial system. Generally, pulse pressure results in stresses acting on the vascular vessel, including longitudinal stress, radial or normal stress, tangential stress or hoop stress and shear stress. This paper explores the relationship between arterial wall shear stress and pulsatile blood pressure with the aim of furthering the understanding of atherogenesis and plaque progression. Methods:We computed the magnitude of the shear stresses within the carotid bifurcation geometry of a patient and calculated the increase in shear stress levels that would occur when the blood pressure and pulse pressures rise during exertion. We also determined in which layer of the artery wall the maximum shear stress is located, and computed the shear stress at different levels within the media. We used the theory of laminate analysis, (Classical Laminate Plate Theory), to analyse the stress distribution on the carotid artery wall. Computational Fluid Dynamics (CFD) analysis was used on anatomy based on a CT angiogram of the carotid bifurcation of a patient with a 90% stenosis on the right side and 10% on the left. The pulsatile non-Newtonian blood flow with a resting blood pressure of 120/80 mmHg and an exertion pressure of 200/100 mmHg was simulated and the resultant forces were transferred to an ANSYS Composite PrepPost (ACP) model for wall shear stress analysis. A multilayer elastic, anisotropic, and inhomogeneous arterial wall (intima, internal elastic lamina, media, external elastic lamina, and adventitial layers) was modelled and the shear stress magnitudes and change over time between the layers was calculated.Results: Shear stress in the individual composite layers is far greater than that acting on the endothelium (less than 5 Pa). At rest, the maximum variation of shear stress in the arterial wall occurs in the intima (138 Pa) and adventitia (135 Pa). The medial layer has the lowest variation of shear stress. Under severe exertion, the maximum shear stress magnitude in the intimal layer and the adjacent medial layer is near the ultimate stress level. The maximum/minimum shear stress ratios during the cardiac cycle vary most widely in the innermost part of the media, adjacent to the intima, with a four-fold ratio increase. This compares with a less than two-fold increase in all the other layers including the intima and adventitia, making the inner media the most vulnerable layer to mechanical injury.Conclusions: This study showed that the magnitude of exertion-induced shear stress approaches the ultimate stress limit in the intima and the immediate adjacent medial layer. The variation in stress is maximal in the inner layer of the media. These findings correlate the site of atheroma development with the most vulnerable site for injury in the media and emphasise the impact of pulse pressure. Further biological studies are required to ascertain whether this leads to injury that initiates atheroma that then precipitates an ...

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

Stress distribution in the walls of major arteries: implications for atherogenesis

Mishani¹,

Belhoul-Fakir²,

Lagat³

et al. 2021

Quant Imaging Med Surg

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“…In general, the OSI parameter describes fluctuations of the flow—it varies from 0, when the direction of the WSS vector is the same as the direction of the flow, to 0.5, when both directions are opposite. It is claimed that high local OSI values, together with low WSS, show regions prone to plaque formation and instances of blood stagnation [ 26 , 27 ]. Wall portions prone to elevated OSI values might indicate regions where blood could clot.…”

Section: Resultsmentioning

confidence: 99%

Porous Media Computational Fluid Dynamics and the Role of the First Coil in the Embolization of Ruptured Intracranial Aneurysms

Wiśniewski

Tomasik

Tyfa

et al. 2021

JCM

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Background: The objective of our project was to identify a late recanalization predictor in ruptured intracranial aneurysms treated with coil embolization. This goal was achieved by means of a statistical analysis followed by a computational fluid dynamics (CFD) with porous media modelling approach. Porous media CFD simulated the hemodynamics within the aneurysmal dome after coiling. Methods: Firstly, a retrospective single center analysis of 66 aneurysmal subarachnoid hemorrhage patients was conducted. The authors assessed morphometric parameters, packing density, first coil volume packing density (1st VPD) and recanalization rate on digital subtraction angiograms (DSA). The effectiveness of initial endovascular treatment was visually determined using the modified Raymond–Roy classification directly after the embolization and in a 6- and 12-month follow-up DSA. In the next step, a comparison between porous media CFD analyses and our statistical results was performed. A geometry used during numerical simulations based on a patient-specific anatomy, where the aneurysm dome was modelled as a separate, porous domain. To evaluate hemodynamic changes, CFD was utilized for a control case (without any porosity) and for a wide range of porosities that resembled 1–30% of VPD. Numerical analyses were performed in Ansys CFX solver. Results: A multivariate analysis showed that 1st VPD affected the late recanalization rate (p < 0.001). Its value was significantly greater in all patients without recanalization (p < 0.001). Receiver operating characteristic curves governed by the univariate analysis showed that the model for late recanalization prediction based on 1st VPD (AUC 0.94 (95%CI: 0.86–1.00) is the most important predictor of late recanalization (p < 0.001). A cut-off point of 10.56% (sensitivity—0.722; specificity—0.979) was confirmed as optimal in a computational fluid dynamics analysis. The CFD results indicate that pressure at the aneurysm wall and residual flow volume (blood volume with mean fluid velocity > 0.01 m/s) within the aneurysmal dome tended to asymptotically decrease when VPD exceeded 10%. Conclusions: High 1st VPD decreases the late recanalization rate in ruptured intracranial aneurysms treated with coil embolization (according to our statistical results > 10.56%). We present an easy intraoperatively calculable predictor which has the potential to be used in clinical practice as a tip to improve clinical outcomes.

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“…Although it is mentioned that the difference between different non-Newtonian models is very small [48][49][50], various researchers have used the non-Newtonian Carreau model in recent years [51][52][53][54][55][56][57][58][59][60]. It is also stated that the Carreau model is in good agreement with the laboratory data of blood [48].…”

Section: Non-newtonian Fluid Model and Boundary Conditionsmentioning

confidence: 99%

The impact of uniform magnetic field on the pulsatile non-Newtonian blood flow in an elastic stenosed artery

Sadeghi

Jahangiri

Saghafian

2020

J Braz. Soc. Mech. Sci. Eng.

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Since the effect of magnetic fields on blood flow is not fully understood or studied comprehensively, this paper, for the first time, addresses the effect of uniform magnetic fields with different intensities on the pulsatile non-Newtonian blood flow in an elastic artery with axially symmetrical single and double stenoses using the commercial software COMSOL Multiphysics 5.1. The results are suggestive that an increase in the percent stenosis increases the pressure drop, which is more dramatic in double stenosis. Moreover, for a given percent stenosis, increasing the Hartmann (Ha) number, in addition to increasing the pressure drop, increases the amount by which the pressure drop is raised. The shear stress results revealed that increasing the magnetic field intensity results in the reduction of the vortex region formed in the back of the stenosis, reducing the area prone to disease, which can resolve pathological issues. The impact of the magnetic field was found to be decreased by increasing the percent stenosis. It was also observed that the percentage difference between the maximum wall shear stresses for various percent stenoses is reduced by increasing the Ha number for both single and double stenoses.

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Numerical solution of the Pulsatile, non-Newtonian and turbulent blood flow in a patient specific elastic carotid artery

Cited by 62 publications

References 59 publications

Stress distribution in the walls of major arteries: implications for atherogenesis

Stress distribution in the walls of major arteries: implications for atherogenesis

Porous Media Computational Fluid Dynamics and the Role of the First Coil in the Embolization of Ruptured Intracranial Aneurysms

The impact of uniform magnetic field on the pulsatile non-Newtonian blood flow in an elastic stenosed artery

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